Maataloustieteellinen A ikakauskirja Vol. 59: 47—50, 1987 Selenium in long term feeding and the frequency of White Muscle Disease in cattle in Finland during the years 1978—1985 HAKON W. WESTERMARCK Department of Pharmacology and Toxicology, College of Veterinary Medicine, SF-00551 Helsinki, Finland Abstract. Selenium deficiency was established in 1961 as the primary cause for WMD in Finland. This started the propylactic treatment with mineral salts containing 0.1 ppm Se as Sodium selenite in Finland officially in 1969, the first in the world. The incidents of WMD decreased from 1.06 % in 1978 to 0.66 % in 1984. If in heifers only from 18 907 cases, 7.9 % to 11 328 cases, 4.6 %, in 1984. The decrease of WMD cases reflects a better Se status in cattle as a whole, and has also contributed to an increase in the Se content in animal products. Even though Se insufficiency was established to be important for animals, the significance of Se for human beings was disregarded, until the consequences of the deficiency in man was demonstrated by T. Wester- marck in 1977. Index words: Selenium, White Muscle Disease. Hardly any other condition in cattle looks more similar to a serious neglection of the maintenance and feeding, than does the White Muscle Disease (WMD). Only a veterinarian is competent to judge, whether the animal in question should get medical treatment or should be taken care of by an inspector for the protection of animals. This is one of the many examples, where the veterinarian is the key person as to the protection of animals. Selenium (Se) deficiency and White Muscle Disease (WMD) in cattle The WMD is a myodegeneration disease most frequent in ruminants. It affects both skeletal and cardiac muscles in animals with Se-deficient diet. In 1961—1962 Se-deficiency was shown to be the primary cause of WMD in the Finnish cattle, when the prophylactic effect of Se- supplementation to the cattle feed was estab- lished in more than one hundred herds with WMD problems. In the trial altogether 384 heifers in these herds were given Vasa Mill mineral salt containing 0.1 ppm Se as sodium selenite and 586 heifers formed the control group. The following year the later group was provided with the Se-mineral salt, which resulted in a decrease in the WMD incidents 47 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=QVFZaQWTexB9Oyb2.PU5Q2qzoyNrGorx1vCF2Yg.89n26vCDcblvLJ7A4YcdJ4mDbROwycOqtsIkH9UapRaTrkHdNXHk5U9Zff5MkuCpKtgnvalb9QBJ97r5O2qNhjHXJEX2JIVCSYag39c8QuUg3uKOYoWvVAyARDQySUD09Djk3M96nmKzlXNKkRx1C_iz7RHn_fFx-6tD8FIwrrWpOg from 17.6. percent to 0.5 %. The other group was left without the Se-supplementation and theWMD frequency increased nearly tenfold (Westermarck 1964). Since 1969 the use of 10 ppm Se, usually as sodium selenite, has been officially ap- proved in mineral salts for cattle in Finland as the first country in the world. In feed com- pounds the Se-supplementation has been 0.1 ppm and in protein concentrates 0.56 ppm. whole country during 1978—1985 varied between 357 kg and 410 kg per year. In the control herds in the coastal area 68 708 ani- mals consumed 59.6 mg Se/Scand. feed unit per animal, and 82 946 animals in the interior consumed only 27.8 mg Se/Scand. feed unit per animal in 1985. In spite of this the WMD incidents were 42.75 % higher in the coastal area than in he interior when starting this study, and still 35.2 % higher in 1985. Even Table 1. The Use of Selenium in Animal Feed During This Study. 1979 1980 1981 1982 1983 1984 1985 Sodium selenite (kg) 2200 2300 2700 2900 2400 3400 4000 Pure selenium (kg) 99 104 122 131 108 153 180 The WMD incidents in Various Parts of Finland During 1978—1985. During 1978—1985 the number of cattle decreased in Finland continuously: cows from 742 000 to 614 000, heifers from 237 000 to 220 000, and calves from 701 000 to 612 000. In this study a frequency comparison was made between two areas: the coastal area and the interior area. The coastal area consisted of two counties, Vaasa and Oulu, situated along the North-West coast of the Gulf of Botnia, and the interior area covering the cen- tral Finland excluding the above mentioned coastal area. In the interior area the number of cattle de- creased from 220 000 to 185 000 and in the coastal area from 210 000 to 191 000 during the time of this study. At the same time the number of heifers in the coastal area decreased from 75 000 to 61 000 and in the interior from 62 900 to 56 600. In 1978 the WMD was treated in 0.37 % of all young animals, e.g. heifers and calves in the interior area, but nearly twice as much eg. 0.68 %, in the coastal area. The actual number of animals suffering from WMD is best elucidated by the percentage of treated WMD cases. The effect of Se supplementation The amount of Se fed to animals in the after a summer with a rainfall of 137.8 mm/ month in the interior, there was a lower fre- quency of WMD than in the coastal area where therainfall was only 103,8 mm/month. The higher incidence of WMD in the coastal area cannot be explained to be caused only by a Se-deficiency or a high rainfall. In 1978 when this study started veterinarians treated 18 907 cases of WMD in Finland, which gave incidents of 1.06 %. As the WMD mostly occurs in heifers and if heifers only are taken into consideration the incidents is 7.98 °7o. In the coastal area the incidents in heifers is then 13.1 °7o and in the interior area 7.5 %. The intensified Se-supplementation to cattle in a continuous frequency decrease of WMD in cattle. Thus in 1984 the WMD had to be treated by veterinarians in 11 328 cases only, and the incidents dropped to 0.68 °7o. The in- cidents dropped more in the coastal area (4.6 °7o) than in the interior (1.4 %). According to Andersson (1960) and Oksa- nen (1965) the WMD frequency was much higher in the coastal area of the North West Finland than in the interior, and occured mostly in heifers. The difference between the high incidence of the WMD in the coastal area and that of the interior has however dimin- ished owing to the increased use of mineral feeds containing Se, but does still exist to a certain degree. 48 4 Table 2. Incidents of the White Muscle Disease, WMD, in Cattle in the years 1978—1985. Year 1978 1979 1980 1981 1982 1983 1984 1985 Number of WMD cases 18 907 16 763 15 341 14 206 12 514 12300 11 328 10 585 Number of cattle (1000) 1 779 1 736 1 738 1 766 1 719 I 588 1 658 1 608 Incident % of WMD 1.06% 0.97% 0.88% 0.77% 0.70% 0.77% 0.68% 0.66% Number of cows (1000) 742 730 719 700 689 658 642 614 Incident % of WMD if exclusive in cows 2.5% 2.3% 2.1% 2.0% 1.8% 1.9% 1.8% 1.7% Number of heifers (1000) 237 238 233 253 224 213 234 220 Incident % of WMD if exclusive in heifers 7.98 % 7.03 % 6.6 % 5.6 % 5.6 % 5.8 % 4.8 % 4.8 % Selenium (Se) 1000 kg/year 40.430 41.038 42.311 37.459 37.626 37.853 37.751 In cattlefeed 10 mg/kg 404 410 423 375 376 378 375 Se mg/day/animal indoors (240 days) 0.94 0.98 1.01 0.88 0.91 0.99 0.94 Se kg/year/animal 0.23 0.24 0.24 0.21 0.22 0.24 0.23 Se as injections ca. g/year 227 200 184 170 150 148 137 127 on Myoselen basis Fertilizer million kg (July—December) 169 245 Fertilizer 6 mg Se per kg 1014 1470 Se in milk 1975 0.017—0.030 ppm 1976: indoors 0.034 ppm, pasture 0.022 ppm, 1986: indoors 0.027 ppm pasture 0.008 ppm The acidity of the soil and perhaps other factors such as high iron and sulphur contents have certainly an influence on the available of selenium to animals and have to be taken in- to consideration as the cause for the suscepti- bility to the White Muscle Disease. The sharp decrease of the WMD in the whole country shows that the Se level has improved. How- ever, it has to be kept in mind that selenium salts and especially organic selenium com- pounds are extremely toxic. The National Research Council (1980) considers that 2 mg Se/kg Dry Matter is the maximum concentra- tion tolerable for all species. Also it is claim- ed, that monogastric animals can tolerate se- lenium compounds better than ruminants do. Summary Selenium deficiency was established in 1961—62 as the primary cause for the White Muscle Disease, WMD, in Finland. This started the prophylactic treatment of the disease with mineral salts containing 0.1 ppm Se as sodium selenite, which was approved in Finland as the first country in the world officially in 1969. This resulted in a continuous decrease in the incidents of the WMD during the period of this study 18 907 cases eg. 1.06 percent in 1978 to 11 328 cases eg. 0.66 percent in 1984. If the WMD had occurred only in heifers the in- cidents had dropped from 7.9 percent to 4.6 percent during the same period. 49 As the number of cattle in Finland decreased during the same period from 742 000 to 614 000 and the heifers from 237 000 to 220 000 the frequency of WMD is more sig- nificant than the actual number of cases. The decrease in the frequency of WMD in cattle reflects a better status in the supply of selenium and has contributed to an increase in the selenium content in animal products. The difference between the incidents of WMD in the coastal area and the interior is, how- ever, dependant also on other factors than selenium deficiency only. References Andersson, P. 1960. Nutritional muscular dystrophy in cattle with special reference to the functional state of the thyroid. VMD Diss. College of Veterinary Medicine, Helsinki. Gissel-Nielsen, G. 1976. Selenium in soils and plants. Proc. Symp. Selenium Tellurium in the environment 1976. Kivinen, E. 1944. Sulfat- eller alunjordar, deras egen- skaper och synpunkter pä deras odling. Svenska Vall- och Mosskultur Tidskr. 2: 1. Oksanen, H. 1965. Studies on nutritional muscular degenerationNMD in ruminants. VMD Diss. College of Veterinary Medicine, Helsinki. Schwartz, K. & K.D. Pathak, 1975. The biological es- sentially of selenium and the development of biologi- REFERAT Selen utfodringens betydelse för frekvensen av vaxarlad muskeldegeneration pä nöt i Finland under ären 1978—1985 Hakon W. Westermarck Under ären 1961 —62 konstaterades att den vaxartade muskeldegenerationen pä nöt i Finland kunde hänföras tili selenbrist. Delta ledde tili att en profylax med selen- haltig mineral med 0.1 ppm Se i form av natrium selenit infördes. Finland var det första land där selentillskottet i denna form godkändes officielt, är 1969. Användningen av selen mineral ökade är för är och led- de tili att frekvensen av den vaxartade muskeldegenera- tion i hela landet minskade frän är 1978 med 18 977 fall (1.06 %) till 11 328 fall är 1984(0.66 %), den kontinuer- ligt sjunkande frekvensen har f.ö. fortsatt och tenden- sen har inte förändrats pätagligt av senare insatt göds- ling med selen. Under är 1986 konstaterades 9 376 fall av muskeldegeneration pä nöt och kornas antal var 599 100 och kvigornas antal 168 700. Even though selenium deficiency was estab- lished to be an important nutritional deficiency in animals, the significance of selenium defi- ciency for human beings was disregarded, until the status in Finnish people and the con- sequences of the deficiency in man was demonstrated by T. Westermarck in 1977 1979. Selenium salts and especially organic sele- nium compounds are, however, extremely toxic and the status of selenium reached in Finland cannot be exceeded, without serious consequences. cally active organoselenium compounds of minimum toxicity. Chem. Scripta 8, p 85—95. Westermarck, H. 1964. Selenium in prevention and therapy in White Muscle Disease in calves and heifers. Nord. Vet. Med. 16: 264—274. Westermarck, T., P. Raunu and L. Lappalainen, 1977. Selenium content of whole blood and serum in adults and children of different ages from different parts of Finland. Acta Pharmacol. Toxicol. 40: 465 —475. Westermarck, T. 1979. Studies on selenium status in the Finnish population with special reference to patients with neuronal ceroid lipofuscinosis. MD Diss. Univer- sity of Helsinki. Ms received February 5, 1987 Under perioden 1978—1985 sjönk antalet nötkreatur i landet frän 742 000 tili 614 000 och antalet kvigor frän 237 000 tili 220 000. Delta gör att frekvensen av muskel- degeneration ger en bättre bild av förhällandena än an- talet fall per är. Den sjunkade frekvensen av muskeldegenerationäter- speglar en förbättrad tillförsel av selen tili nötkreaturen och bidrar tili en högre hait av selen i animalie produk- terna. Skillnaden mellan frekvensen av muskeldegenera- tion i kustomrädena och det inre av landet, trots tillför- seln av selen visar att även andra faktorer än selenbrist spelar en roll vid uppkomsten av muskeldegeneration pä nöt. Även om betydelsen av ett selentillskott för djurens hälsa redan tidigt vann burskap inom veterinärmedicinen i Finland ignorerades selenets betydelse för människan, tills T. Westermarck’s undersökningar under ären 1977 1979 pävisade delta spärelements betydelse. Selensalten och särskilt dä selen i organisk form är extremt toxiska och när optimal! selenstatus uppnätts i värt land kan yt- terlig tillförsel medföra allvarliga konsekvenser. 50